1. Prepare for the worst - Hope for the best. This comes right from the advice of Dale Carnegie in "How to Stop Worrying and Start Living". Accept the worst possible outcome and then take action to improve upon the worst.
2. Get Busy. When you find yourself beginning to worry - get busy on your to-do list. If you don't have a list - then write one. List your goals and the action steps required to meet them. One of the benefits of your to-do list is you will stop worrying about forgetting something important.
3. Distract Yourself. Call a friend. Read a good book. Watch a funny movie. Take the kids to the park. Take a walk. There's dozens of things you can do.
4. Get Support. Friends and family can be an excellent source of support. Especially if they will tell you how they see things. Sometimes just talking things out, helps the worry go away.